Will,
On 08/11/2014 06:24 PM, Will Deacon wrote:
On Fri, Aug 08, 2014 at 08:35:42AM +0100, AKASHI Takahiro wrote:
On 08/06/2014 12:08 AM, Kees Cook wrote:
On Fri, Jul 25, 2014 at 2:37 AM, AKASHI Takahiro
<takahiro.aka...@linaro.org> wrote:
I found a bug in my current patch (v5). When 32-bit tracer skips a system call,
we should not update syscallno from x8 since syscallno is re-written directly
via ptrace(PTRACE_SET_SYSCALL).
Ah, yes. Will aarch64 have a PTRACE_SET_SYSCALL option, or is this
strictly a 32-bit vs 64-bit issue?
As discussed in a few weeks ago, aarch64 won't support PTRACE_SET_SYSCALL.
Well, I don't think anything was set in stone. If you have a compelling
reason why adding the new request gives you something over setting w8
directly, then we can extend ptrace.
Yeah, I think I may have to change my mind. Looking into __secure_computing(),
I found the code below:
> case SECCOMP_MODE_FILTER:
> case SECCOMP_RET_TRACE:
> ...
> if (syscall_get_nr(current, regs) < 0)
> goto skip;
This implies that we should modify syscallno *before* __secure_computing()
returns.
I assumed, in my next version, we could skip a system call by overwriting
syscallno
with x8 in syscall_trace_enter() after __secure_computing() returns 0, and it
actually
works.
But we'd better implement PTRACE_SET_SYSCALL to comply with what
__secure_computing()
expects.
-Takahiro AKASHI
Will
_______________________________________________
linux-arm-kernel mailing list
linux-arm-ker...@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
